Lumbar scoliosis with degenerative changes in the elderly presents with spondylosis, variable apophyseal joint arthrosis, laminar hypertrophy, and marginal osteophytos most prominent within the scoliotic apex. Resultant lumbar stenosis, alone or with ventral spurs and herniated discs as isolated or associated lesions, can produce disabling low-back and lower extremity pain, weakness, and neurogenic claudication relievable by appropriate decompressive surgery. Myelography is essential as a preoperative measure. Whether such scoliosis is superimposed on adolescent thoracolumbar scoliosis or arises anew in later life remains an open question.

Adult↗

PubMedDate not supplied

An analysis of hypoxia in sheep brain using a mathematical model.

Cerebral blood flow (CBF) increases as arterial oxygen content falls with hypoxic (low PO2), anemic (low hemoglobin) and carbon monoxide (CO) (high carboxyhemoglobin) hypoxia. Despite a higher arterial PO2, CO hypoxia provokes a greater increase in CBF than hypoxic hypoxia. We analyzed published data using a compartmental mathematical model to test the hypothesis that differences in PO2 in tissue, or a closely related vascular compartment, account for the greater response to CO hypoxia. Calculations showed that tissue, but not arteriolar, PO2 was lower in CO hypoxia because of the increased oxyhemoglobin affinity with CO hypoxia. Analysis of studies in which oxyhemoglobin affinity was changed independently of CO supports the conclusion that changes in tissue PO2 (or closely related capillary or venular PO2) are predictive of alterations in CBF. We then sought to determine the role of tissue PO2 in anemic hypoxia, with no change in arterial and little, if any, change in venous PO2. Calculations predict a small fall in tissue PO2 as hematocrit decreases from 55% to 20%. However, calculations show that changes in blood viscosity can account for the increase in CBF in anemic hypoxia over this range of hematocrits.

Algorithms↗

PubMedDate not supplied

Epidural analgesia for postoperative pain control in children.

Ninety-eight continuous postoperative epidurals were administered to 87 children. The patients were divided into two groups: group I included 63 cases in which a 0.0625-0.25% solution of bupivacaine was continuously administered; group II included 35 cases in which a similar solution of bupivacaine mixed with 2-10 micrograms of fentanyl was administered. The dose of the epidural medication was titrated by the anesthesiologist according to the patient's age and anticipated level of postoperative pain. The average pain score for all patients for the first 48 h was 1.43. Supplemental analgesia averaging 0.132 mg intravenous morphine/kg/8 h was required in 49 cases (41 in group I and eight in group II). In group I, the average dose of supplemental analgesia was 0.144 mg intravenous morphine/kg/8 h, whereas in group II, it was only 0.056 mg intravenous morphine/kg/8 h. Continuous epidural analgesia is effective in controlling postoperative pain, and the addition of fentanyl reduces the need for systemic narcotics.

Adjuvants, Anesthesia↗